The CNT family (peptide transporters) encompasses multiple transmembrane proteins, primarily responsible for the transport of peptides and amino acids inside and outside of cells. Members such as CNT1, CNT2, and CNT3, all possess specific transmembrane structures and are widely distributed in tissues such as the intestines, kidneys, and brain, playing a crucial role in the absorption of nutrients and the regulation of neurotransmitters. These transporters operate through a sodium-dependent mechanism, affecting the cellular uptake and metabolism of key nutrients. Variations and mutations in gene expression can lead to changes in transporter function, associated with a variety of diseases, including metabolic disorders and digestive system diseases.